Crestron electronic 3.5, 2.5, 1.5 service manual Natural gas, Propane Gas

Page 32

6 Gas connections

￿WARNING Use two wrenches when tightening gas piping at boiler (FIG. 6-2), using one

wrench to prevent the boiler gas line connection from turning. Failure to support the boiler gas connection pipe to prevent it from turning could damage gas line components.

Figure 6-2Inlet Pipe with Backup Wrench

USE BACK UP WRENCH TO PREVENT

PIPE FROM ROTATING

NOTICE

Maximum inlet gas pressure must not

exceed the value specified. Minimum

 

 

value listed is for the purposes of input

 

adjustment.

Natural gas:

￿WARNING Check boiler rating plate to determine which fuel the boiler is set for. Crest

boilers CANNOT be field converted. Failure to comply could result in severe personal injury, death, or substantial property damage.

Pipe sizing for natural gas

1.Refer to Table 6B for pipe length and diameter. Based on rated boiler input (divide by 1,000 to obtain cubic feet per hour).

a.Table 6B is only for natural gas with specific gravity 0.60 inches, with a pressure drop through the gas piping of 0.5 inches w.c.

b.For additional gas pipe sizing information, refer to the National Fuel Gas Code, NFPA 54 / ANSI Z223.1 - latest edition, or in Canada CSA B149.1 Installation Code.

32

Installation & Operation Manual

Natural gas supply pressure requirements

1.Pressure required at the gas valve inlet pressure port:

•Maximum 14 inches w.c. (3.5 kPa) with no flow (lockup) or with boiler on.

•Minimum 4 inches w.c. (.99 kPa) with gas flowing (verify during boiler startup).

2.Install 100% lockup gas pressure regulator in supply line if inlet pressure can exceed 14 inches w.c. (3.5 kPa) at any time. Adjust lockup regulator for 14 inches w.c. (3.5 kPa) maximum.

 

￿ WARNING

Ensure that the high gas pressure regulator

 

 

is at least 10 feet (3 m) upstream of the

 

 

 

 

appliance.

Propane Gas:

 

 

Check boiler rating plate to determine which

 

￿ WARNING

 

 

fuel the boiler is set for. Crest boilers CAN

 

 

NOT be field converted. Failure to comply could result in severe personal injury, death, or substantial property damage.

Pipe sizing for propane gas

1.Contact gas supplier to size pipes, tanks, and 100% lockup gas pressure regulator.

Propane Supply Pressure Requirements

1.Adjust propane supply regulator provided by the gas supplier for 14 inches w.c. (3.5 kPa) maximum pressure.

2.Pressure required at gas valve inlet pressure port:

•Maximum 14 inches w.c. (3.5 kPa)with no flow (lockup) or with boiler on.

•Minimum 4 inches w.c. (.99 kPa) with gas flowing (verify during boiler startup).

￿ WARNING Ensure that the high gas pressure regulator is at least 10 feet (3 m) upstream of the

appliance (FIG. 6-3).

Figure 6-3Gas Supply Piping to Regulator

 

 

 

10'

 

 

 

 

 

 

 

 

* GAS PRESSURE

 

 

 

MINIMUM

 

 

 

 

 

 

 

 

 

 

 

 

 

REGULATOR

 

 

 

 

 

 

 

 

 

 

 

 

(FIELD SUPPLIED)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

* MANUAL SHUT OFF VALVE (FIELD SUPPLIED)

* REQUIRED FOR INSTALLATION IN THE COMMONWEALTH OF MASSACHUSETTS

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Contents Save this manual for future reference Contents When servicing boiler Please read before proceedingCrest How it works BlowersCrest How it works Models 1.5 2.0 2.5 3.0 Ratings Crest Ahri RatingInstallation must comply with Determine boiler locationBefore locating the boiler, check Provide clearancesProvide air openings to room Flooring and foundationVent and air piping Prevent combustion air contaminationAreas likely to have contaminants When using an existing vent system to install a new boilerProducts to avoid When removing a boiler from existing common vent system Remove boiler from wood pallet 7Combustion Air from Outside Single Opening Minimum Recommended Combustion AIR Supply to Equipment Room Optional room air General ventingDirect venting Install vent and combustion air piping Air inlet pipe materialsApproved Stainless Steel Vent Manufacturers Make Model Air intake/vent connectionsRemoving from existing vent Common venting Vertical direct venting Vent/air termination verticalDetermine location Prepare roof penetrationsMultiple vent/air terminations 4Alternate Vertical Terminations with Multiple BoilersSidewall direct venting Vent/air termination sidewallPrepare wall penetrations 2Clearance to Doors and WindowsRoom air 4Multiple Vent Terminations must also comply with FigureHydronic piping 20F 40F 60F Circulator sizingModel Near boiler piping components System Multiple Boilers Common Header Primary / Secondary Flow For all equipment and detailing required by local codes Hydronic piping Model Gas Inlet Size Connecting gas supply pipingGas connections Natural gas Propane GasGAS Piping Size Chart Check inlet gas supplyGas valve replacement Gas PressureLine voltage connections Field wiringInstallation must comply with Enable Outdoor temperature sensorLouver proving switch Low voltage connectionsAuxiliary switch 1 Alarm contactsWiring of the cascade System supply sensorWiring FieldCondensate disposal Condensate drainFreeze protection when used Start-upCheck/control water chemistry Fill and test water systemCheck for gas leaks Check thermostat circuitsInspect condensate system Inspect/check condensate lines and fittingsFinal checks before starting the boiler Start the boilerIf boiler does not start correctly Check system and boilerFor Your Safety Read Before Operating Set space heating operation Gas Natural Gas Propane ValveSet clock Verify HWG circulator mode Set HWG target temperatureConfiguration of the cascade Operating information GeneralProtection features Boiler temperature regulation Outdoor reset operation, if usedCascade Sequence of operation Crest control module Home Screen2Main Menu Screen Maintenance Maintenance and annual startup Service technicianOwner maintenance See the Crest User’s Information Manual for InstructionsMaintenance Flue vent system and air piping Check water systemCheck expansion tank Check boiler relief valveCheck ignition ground wiring Check all boiler wiringCheck control settings Check flame signalCleaning boiler heat exchanger Review with ownerHandling ceramic fiber materials Niosh stated First AidDiagrams Integrated Control2Wiring Diagram
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